*2.5. Water Vapor Permeability*

In edible films, water vapor permeability (WVP) significantly impacts the shelf life and the quality of the packed food product. The WVP of an edible film is dependent on the properties of the film-forming material, such as its composition and structure. The environmental conditions, such as the temperature and humidity of the storage environment, can also affect the WVP of the hydrogel-based films. A lower WVP is desirable for certain applications as it slows down moisture migration and increases the shelf life of the product. The water vapor permeability of the SA–AG composite films significantly decreased with the addition of the CEO (Table 1). The maximum WVP (0.424) was exhibited by the control compared with the film samples loaded with the CEO. The AC-4 sample showed the minimum WVP (0.353), followed by the AC-3 (0.390) and AC-2 (0.405) samples. The decrease in the WVP could be due to the hydrophobicity of the CEO, which resulted in better barrier properties for the hydrogel-based films regarding water vapor permeability. The results of the current study are in line with the findings of Suput et al. [26] and Sánchez-González et al. [27]. Furthermore, the WVP of the edible films also depends on the type of polymers used, the concentration of the oil, and the preparation technique and conditions.
